Wiring an LLM as a first-class Yjs peer is architecturally sound — but it invalidates three silent assumptions your collaboration stack already makes about peer symmetry: throughput, undo ownership, and presence cadence. You've tuned a Yjs provider under real collaborative load. You know the feeling before you can name it — one heavy client starts lagging the room, presence updates stutter, and you end up adding a debounce somewhere and calling it done. Now imagine that client generates text at